Flame photometer

ABSTRACT

This invention relates to a flame photometer having a transport tape, external to the gas burner, for transporting a measured portion of sample material from a remote location to the spectral flame for analysis.

United States Patent 1 3,586,446

[72] Inventors Eugene Findl 3,036,893 5/1962 Natelson 23/253 Granada Hills; 3,088,364 5/1963 Rosza et a1. 356/38 Mani L. Bhaumik, Pasadena; lsidor M. 3,128,619 4/1964 Lieberman 23/255 Schneider, Los Angeles, all of, Calif. 3,211,050 /1965 Pelavin 356/187 [21 1 Appl. No. 667,693 3,376,694 4/1968 Owens et al 73/231 X [22] Filed Sept. 14,1967 3,419,359 12/1968 Anderson et a1 23/253 [45] Patented ,)I(une 25:, 1971 I OTHER REFERENCES ang Lockyer; J. Norman THE SPECTROSCOPE AND ITS AP- PLlCATlONS, MacMillan and Company, London and New York, 1873, pages 42- 45 relied on Landauer et a1., SPECTRUM ANALYSIS, John Wiley & [54] FLAME PHOTOMETEF Sons, New York, 1907, pages 52 relied on.

031m Drawmg Willard et 31., INSTRUMENTAL METHODS OF ANALY- [52] U.S. Cl 356/187, 515, 3rd edition, Princeton, New Jersey, Van Nostrand Com- 356/87, 356/36 pany, Inc, 1958, pages 96 and 97 GD 61 W67 1958 [51] Int. Cl "83011 231033 Primary Examiner Ronald L wiben Assistant Examiner-F. L. Evans [50] new Attorneys-Ronald Zibelli, James J. Ralabate, Paul M Enlow l I and Norman E. Schrader [56] References Cited UNITED STATES PATENTS ABSTRACT: This invention relates to a flame photometer 2,280,993 4/1942 Barnes...., 356/103 having a transport tape, external to the gas burner, for trans- 2,451,501 10/1948 Liben 250/228 X porting a measured portion of sample material from a remote 2,883,901 4/1959 Danielsson 356/38 location to the spectral flame for analysis.

{52 J 6'0 0 PTIO NA L f 74 f CALIBRATION SAMPLE 64 STANDARD PHOTO l0 ALIQUOTER AUQUQTER DETECTOR 48 M-ILV/ //I|"ll //I' /[Y/ l -m' ///AlT-.-i]lr/ will /.I' \[lg/ //|J|| n|1] FUEL SUPPLY 72 OXIDIZER SUPPLY tamination is a significant problem unless FLAME PI-IOTOMETER BACKGROU ND OF TH E IN V ENTION This invention relates to automatic chemical analysis and, more particularly, the invention relates to flame photometry. Although not limited thereto, the present invention is particularly adapted for use in the analysis of body fluids, such as blood, urine, etc., and for the determination of the amount of sodium, potassium, calcium, etc. present therein.

Using well known flame photometric techniques, a lithium salt, such as lithium chloride or lithium nitrate, is added to the sample blood serum to provide the sample with an internal standard or reference. When the sample containing the calibration standard is introduced into the flame of the burner, a quantitative determination of the constituent under analysis is obtained by transmitting the spectral light corresponding to the spectral line of the constituent to a photosensitive device to provide a current which is proportional to the amount of said spectral light, and the spectral light corresponding to the spectral line of lithium is simultaneously transmitted to another photosensitive device to provide another current which is proportional to the amount of said spectral line. An indicating system, operable under the control of a null-type balance current ratio system, indicates the ratio of the currents as a measure of the quantity of the constituent under analysis present in the blood sample.

Although highest accuracies are generally obtained utilizing the lithium standard ratio approach, it is not an absolute requirement that such an approach be utilized. By maintaining precise control of the flame size, flame temperature and sample size, measurement of the spectral emission intensity of the sample alone will provide an accurate measure of the quantity of constituent under analysis.

Presently available spectrochemical analytical units relating to flame photometry employ liquid flow systems wherein the fluid to be analyzed is aspirated into the flame of the burner along with the calibration standard. Although the available instruments vary in structural detail, they all contain the following essential parts: a high temperature gas flame burner, a liquid flow system for accurately aspirating the sample to be analyzed into the ing the light energy from the thermally excited vapor.

The aforementioned devices have significant disadvantages in maintaining proper conditions under which the sample to be analyzed is aspirated into the flame. Proper aspiration of the sample material is a delicate problem and the minute valves and flow lines required for such aspiration tend to become clogged and dirty after repeated use. Daily shutdown for cleaning is generally required. Different samples of varying concentration and composition are caused to flow through the same conduit prior to aspiration. Thus, sample cross-conelaborate auxiliary apparatus is provided to periodically and, preferably after each sample, clean the sample flow lines and the burner into which the sample is aspirated. Such cleaning systems and apparatus are basically incompatible with the burner which it must clean and through which the cleaning material would have to flow.

In addition, the burner designs presently employed require relatively large amounts of combustible gas flow, generating a considerable quantity of heat and noise. Further, as indicated above, such burner designs require the use of lithium salt additives since precise control of the large flames and quantities of sample are not feasible.

OBJECTS OF THE INVENTION It is therefore, an object of this invention to provide a flame photometer which is not subject to the aforementioned disadvantages.

A further object of the present invention is to provide a flame photometer having a burner which does not have sample supply means flowing therethrough.

flame, anda spectrophotometer for measur- A further object of the present invention is to provide a flame photometer having sample supply means which does not aspirate the sample material into the flame of a gas burner.

It is a further object of the present invention to provide a flame photometer having sample supply means which are totally external to the burner.

It is a further object of the present invention to provide a flame photometer which does not have an elaborate sample flow system which is subject to cross-contamination of sample material.

A still further object of the present invention is to provide a method wherein sample aliquots are accurately transported to the burner of a flame photometer.

Still a further object of the present invention is to provide a method of flame photometric analysis wherein the sample to be analyzed is not aspirated into the flame but transported to said flame by means external to the burner.

Still a further object is to provide a novel carrier for transporting sample aliquots to the flame of a flame photometer.

The above and still further objects, features, and advantages of the present invention will be apparent by consideration of the flowing detailed disclosure of specific exemplary embodiments of the invention.

SUMMARY OF THE INVENTION The above and still further objects of the present invention are achieved by providing a flame photometer having, in its essential elements, a transport tape bearing a plurality of sample-confining storage sites, means to transfer a measured portion of sample material from a remote location to one of said storage sites, a gas burner, means to advance said transport tape past said sample transfer means and into the flame of said gas burner, and spectrophotometric detecting means for analyzing the light energy emitted from the thermally excited sample material. Optionally, means can be provided to deposit a calibration standard on said storage site along with said sample portion. Said calibration standard deposition means being situated along the path of tape travel before the gas burner. In this optional embodiment, the spectrophotometric detecting means should be capable of separately analyzing the thermally excited calibration standard vapor simultaneous with its analysis of the thermally excited sample material vapor thereby providing a reference standard upon which to base the quantitative analysis of the constituent present in the sample material.

The transport tape of the present invention includes a noncombustible supporting substrate having discrete sample-confining storage areas for deposition and retention of small aliquots of sample material. In one embodiment, regularly spaced apertures are provided in the noncombustible supporting substrate, each aperture having disposed thereover a porous combustible disc upon which the sample and the calibration standard, if desired, are deposited. In one mode of operation, the calibration standard is preimpregnated into the combustible material by well-known immersion and drying processes. In a further and preferred embodiment, a porous layer or disc is sandwiched between two noncombustible layers, each of the noncombustible layers having regularly spaced apertures therein with the aperture in the upper layer being aligned over the aperture in the lower layer. There is thus provided a sample-confining storage site, access to which can be had through the aperture in the upper layer for deposition of the sample material and, if desired, a calibration standard. Thereafter, the 3-layered transport tape can be brought into position over the burner flame which can contact the sample storage site through the aperture in the lower layer. In either embodiment, a hydrophobic barrier layer can be provided which will limit transfer or diffusion of materials deposited on the storage site. In its simplest form, such a barrier comprises an annular ring having an inside diameter slightly greater than the placed. The barrier will thus maintain the deposited materials diameter of the aperture about which it is on the storage site but will not interfere with the subsequent analysis. However, in the preferred embodiment, such a barrier is not necessarily required. Further, the need for said barrier can be obviated by drying the sample material after deposition, as will be described hereinafter.

In its broadest aspects, the present invention achieves its objectives by providing a microburner flame and means external to the gas burner for transporting the sample to be analyzed to the flame. By utilizing a transport tape, as previously described, it is unnecessary to provide sample flow conduits of minute diameter within the burner. By providing individual sample-retaining storage sites, it is unnecessary to flow different samples of varying concentration and composition through the same conduit prior to aspiration in the burner flame. By utilizing a microburner noise and heat generation are negligible and gas flow minimal. Accordingly, the present invention eliminates the need for intricately designed burners having minute sample transportation conduits properly machined and positioned for accurate aspiration of sample material into the flame. It also eliminates the necessity of cleaning the burner to limit or reduce cross-contamination or the tendency of the burner to be clogged with insufflciently aspirated material.

Procedurally, the advantages of the present invention are achieved by providing a transport tape having discrete sampleconfining storage areas for deposition and confinement of an aliquot of sample material, transferring an aliquot of sample material from a remote location to one of said sample storage areas, moving said sample-containing storage area on said .transport tape onto position above the burner flame and monitoring with a spectrophotometer the light energy emitted from the thermally excited vapor. Thereafter, the aforementioned steps are repeated for successive samples.

BRIEF DESCRIPTION OF THE DRAWINGS The nature of the invention will more easily be understood when it is considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a greatly enlarged side sectional view of the preferred embodiment of the transport tape of the present invention;

FIG. 2 is a greatly enlarged side sectional view ofa transport tape of the present invention;

FIG. 3 is a schematic representation of the analytical method of the present invention and the apparatus therefore;

FIG. 4 is an enlarged perspective view of an automatic flame photometer as contemplated by the present invention;

FIG. 5 is a schematic representation of a spectrophotometer for use with the present invention; and

FIG. 6 is a top view of FIG. 5.

Referring to FIG. 1, there is seen the presently preferred embodiment of the transport tape 10 of the present invention wherein porous layer 30 is sandwiched between noncombustible layers 32 and 34. Apertures 36, 38, 40, etc. are provided in layer 32 and apertures 42, 44, 46, etc. are provided in layer 34 with the apertures being aligned on opposite sides of porous layer 30. There is thus provided sample storage sites 48, 50, 52, etc. to which access may be had through the apertures on either side thereof. For example, a sample aliquot may be added to storage site 48 through aperture 42 and thereafter the flame of a gas burner can be caused to impinge upon the underside of the sample storage site 48 through aperture 36.

If desired, lateral diffusion or transfer of liquid materials from these storage sites can be eliminated by provision of a suitable barrier B in the form of an annular ring having an inside diameter slightly greater than the diameter of the underlying aperture. As shown, storage site 52 has barriers B, which will limit the lateral transfer of materials added to said storage sites.

Referring to FIG. 2, there is seen an enlarged side sectional view of a transport tape of the present invention. Tape 10 has a noncombustible supporting substrate 12 which has regularly spaced apertures l4, l6, 18, etc., therein. Disposed over each aperture and supported by substrate 12 are porous discs 20, 22, 24, etc. for the addition and retention ofa sample aliquot and, if desired, a portion of calibration standard.

Referring to FIG. 3, there is shown, by way of schematic representation, a flame photometric analyzer utilizing the transport tape of FIG. 1. Transport tape 10, having sample storage sites 48, 50, 52, 54, 56 and 58 aligned over apertures 36, 38, 40, 42, 44 and 46, respectively, is advanced from a supply roll (not shown) by advancing means (also not shown). Such means are well known in the art and form no part of the present invention except as they may be necessary for the effective operation of the herein disclosed apparatus. For example, tape 10 can have sprockets therein and be passed over a sprocket wheel which will successively index the tape from position to position. Tape 10 passes beneath a sample aliquoter 60 and, as previously indicated if desired, an optional calibration standard aliquoter 62. As shown, the measured portion of sample material and the measured portion of the calibration standard are added at the same position through an aperture 64 in the upper noncombustible layer. This addition at the same station is not critical and, accordingly, can be achieved at different stations or by having the calibration standard, such as lithium salt, impregnated in the porous media as is desired. Furthermore, the same aliquoter can be utilized for the addition of both materials to the sample storage site. Tape 10 is successively indexed forward until it reaches position T directly over the vertically positioned burner 66 having flame F. To prevent undesirable heat effects, burner 66 can be pivoted at point 68 from the dotted position to the vertical solid line position as shown. Alternately, the burner can be caused to reciprocate in a vertical manner whereby the flame F will be caused to successively impinge upon successive storage sites but will be withdrawn from the test position during successive indexing of the tape. Fuel and oxygen for burner 66 are supplied, respectively, from fuel supply 70 and oxidizer supply 72. Light emitted by the vaporized sample material is analyzed by detector 74 appropriately positioned to receive light emanating from the spectral flame. Detectors suitable for this purpose, and techniques for their use, are well known and it is believed unnecessary to lengthen this specification with such information as reference may easily be had to the prior art.

Referring to FIG. 4, there is seen a transport tape 10 bearing a plurality of discrete sample-confining storage sites being unwound from supply reel 80, threaded through a plurality of stations, and being successively indexed forward by drive means 82. A sample wheel 84 is provided having a plurality of cavities for the storage of various samples. An aliquoter 86 withdraws a measured portion of sample material from one of said cavities and transfers said measured portion to a discrete storage site on tape 10. In the dotted position as shown, aliquoter 86 has a measuring tube which is inserted into the sample material and operatively connected to a source of vacuum which draws a predetermined amount of liquid sample into the measuring tube. When the tube is filled, a drop is formed on the interior end thereof. This drop is sensed detection means 88 comprising a lamp and a photocell. The aliquoter is caused to oscillate until the tip of the measuring tube is positioned directly over the storage site on the transport tape. Slight pressure is placed on the internal end of the measuring tube forcing the liquid contents thereof out of the tube and onto the storage site. After passing through drying station 90 the sample-containing storage site passes directly over micro-burner 92. Drying has been found to provide better analytical results in that noncritical portions of the liquid sample are eliminated from the storage site and, therefore, do not mask or otherwise alter the photometric analysis. Without drying, the carrying liquid or liquid sample which has to be vaporized slows down the burn thereby resulting in a more erratic burn. With drying, this material is eliminated whereby more reliable and more reproducible analytical results can be obtained. The spectral flame F is detected by photodetectors 94. The results of the analysis can be computed automatically'and recorded on sheet 96 by recorder 98. After analysis, tape I is wound upon a takeup reel connected to drive means 82 and can be stored or discarded as is desired.

An exemplary sample aliquoter or calibration standard aliquoter is shown in Ser. No. 602,080 filed Dec. 15, 1966 now U.S. Pat. No.'3,508,879 assigned to the assignee of the present invention. The automatic aliquoter and the analytical apparatus as shown in said copending application are incorporated herein by reference; it being understood that the flame photometer of the present invention is a suitable adjunct to the automatic analytical apparatus as disclosed in said copending application.

If desired, a self-contained or internal fuel supply can be provided with the flame photometer of the present invention. For example, water from a distilled water supply is fed into an electrolyzer on a demand basis. The electrolyzer decomposes the water into hydrogen and oxygen which are then fed by appropriate conduits to the burner. Ignition at the burner can be achieved in any suitable manner as, for example, by a platinum black igniter adapted for automatic ignition upon activation of the distilled water supply and the electrolyzer. Provision of this internal fuel supply eliminates the need for an external, bulk supply while simultaneously reducing the overall size of the flame photometer.

Referring to FIGS. and 6 there is seen a spectrophotometer, such as one which can be utilized with the apparatus of FIG. 4 and which does not directly view the thermally excited vapor. Certain details of construction have been omitted to simplify the drawings and make the essential components more readily ascertainable. Tape 10 having sample material deposited on at least one sample storage site passes between the flame of a gas burner (not shown) and spectrophotometer 100. In the analytical position T, the flame and the storage site having the sample under analysis are positioned directly beneath flame chamber 102. The light from the thermally excited vapor passes through an opening 104 in flame chamber 102 into a cylindrical chamber 106 coated with a diffuse reflector of light, such as magnesium oxide. The top and bottom of chamber 106 are closed. Light entering chamber 106 attains a uniform radiation density by successive reflections at the diffusely reflective walls of the chamber. Photodetectors 108 and 110 having photomultiplier tubes I12 and 114 view this uniform radiation through openings I16 and I18 in the chamber wall. Positions 120 and 122 are provided in photodetectors 108 and H0, respectively, for the insertion of appropriate filters so that each photodetector can receive only a desired wavelength or wavelengths. Areas 124 and 126 are provided for the storage of the associated electrical components. Terminals (not shown) are also provided for connection to the recording devices. The top wall of flame chamber 102 has a vent or opening 128 therein for the egress of analyzed vapor, An exhaust tube, connected to a source of vacuum can be positioned over vent 128 if desired. As the remainder of the walls are opaque, extraneous light is prevented from reaching chamber 106 and photodetectors 108 and 110. This indirect viewing by the photodetectors of the spectral light is necessitated by the fact that the thermally excited vapor giving the spectral light tends to wander laterally thereby presenting slightly differing geometry to direct viewing photodetectors. This inaccuracy is eliminated by the above-described spectrophotometer as a uniform radiation density is achieved within chamber 106 and it is this radiation which is viewed by photodetectors I08 and 110.

As previously described, the transport tape of the present invention comprises a noncombustible supporting substrate bearing a plurality of sample-confining storage sites available for deposition and retention of small aliquots of sample material. The sample-confining storage areas are either positioned over an aperture in the underlying noncombustible support or sandwiched between aligned apertures in noncombustible layers on opposite sides of the storage site. It is through the apertures that the sample material and/or the calibration standard material is deposited upon the storage site and the flame of the burner caused to impinge upon the storage site after appropriate deposition of the desired material.

Any suitable noncombustible material of sufficient strength can be utilized to provide thenecessary support for the transportation of the sample-confining storage sites. It ispreferred that the supporting material be sufficiently flexible so that it can be wound around a supply reel whereby a large quantity of transport tape can be stored in a minimum of space. Typical materials include aluminum foil, copper foil, tantalum foil, brass foil, etc.

The storage site of the present invention may take on many forms. For example, as shown in FIG. 2, the storage site is a porous disc situated over an aperture in the underlying supporting substrate whereas in FIG. I, the storage site is a continuous layer, sandwiched between two layers of noncombustible material. By porous it is meant that the disc or layer is, at least, capable of being impregnated with the necessary materials with the result that said materials are stored for as long as necessary within the designated site. With respect to the embodiments shown in FIG. I, the storage site may be enclosed with a hydrophobic barrier B, such as paraffin wax, which will prevent the transfer or diffusion of the deposited materials from the storage site. In its simplest form, barrier B has a diameter which is only slightly greater than the diameter of the underlying aperture in the noncombustible layer. It can thus be positioned to be protected by the noncombustible layer from the burner flame and to maintain substantially all the deposited material(s) in the storage site. The storage site should be formed of a material which will not adversely effect the light emanating from the vaporized sample material or calibration standard. By adversely" it is meant that the storage site neither adds to the spectrolight emanated from the deposited materials nor masks, modifies or otherwise alters the emanated light so as to give an inaccurate reading. Obviously, the storage site should initially be free of the constituent or constituents in the sample material under analysis. The calibration standard may, however, be impregnated therein. Additionally, to provide for a fundamentally clean operation or one as clean as possible, the storage site, after burning, should leave as little ash or residual as possible. Low ash or low residual filter papers are well known in the art and can be utilized in the practice of the present invention provided they meet the other requirements as set forth in this paragraph. Suitable materials for use as the storage site of the present in vention include de-ionized nitrocellulose, Schleicher and Schnell N0. 589 filter paper, acid washed Whatman No. 541, acid washed Whatman No. 42, etc.

In general, uniformity of materials and operation is desirable throughout the functioning of the present invention. For example, best results can be obtained when the center of the storage site is positioned at the same spot directly over the flame of the microbumer and properly positioned for optical analysis of the spectral flame. With respect to the materials, it is desirable to have a paper of uniform composition, thickness, size and storability of liquids, etc. As deviations from uniformity become greater, it is desirable to modify the photometric procedure whereby a calibration standard is also deposited upon the storage site. A ratio analysis is utilized which compensates for the aforesaid deviations as well as other deviations which may inherently occur during the opera tion of the apparatus of the present invention. It should be understood, of course, that a ratio analysis can be used even though nonuniforrnities are kept to a minimum.

The amount of sample material vaporized by the flame of the gas burner is a function of the size of the aperture through which the material is added and the storage capability of the sample storage site. If the thickness of each porous media storage site is constant and the size of the aperture is constant, the amount of sample available for vaporization will be relatively constant provided sufficient material is added to saturate the site. If at least the saturation amount of material is ,material the need for a barrier to prevent contamination of one spot to the other is eliminated if the volatile material is shortly thereafter removed by drying. Drying eliminates the carrier and prevents cross contamination by diffusion along a continuous porous media path.

DESCRIPTION OF THE SPEClFlC EMBODIMENTS The following examples are given to enable those skilled in the art to more clearly understand and practice the invention. They should be considered not as a limitation upon the scope of the invention but merely as being illustrative thereof.

The transport tape utilized in these examples comprises a Schleicher and Schnell No. 589 acid washed, cellulosic filter paper sandwiched between apertured aluminum foil layers, as described above. Said transport tape is stored on a supply reel and advanced through a sample addition station and an analytical zone having a microburner supplied with propane and oxygen before being stored on a takeup reel. The microburner oscillates back and forth between a nonanalytical position and the analytical position wherein the flame of the burner impinges upon the underside of the storage site. The oscillation of the microburner is operatively connected with the indexing of the transport tape so that as a storage site is brought into the analytical zone the microburner is oscillated into the vertical, or analytical, position. The spectral light emitted from the vaporized sample material is reflected from a magnesium oxide coated reflector to a spectrophotometer having a photomultiplier detection tube. Said spectrophotometer is disposed on the opposite side of the transport tape from the microburner and has, for sodium analysis, a 589 millimicron filter and 2.0 density filter. After analysis, the microburner moves to the nonanalytical position and the transport tape is indexed forward. The cycle now repeats itself when the storage site is moved into the analytical zone and the microburner oscillates to the analytical position directly beneath the storage site.

EXAMPLES l-X A 10 microliter aliquot of an aqueous sodium chloride solution having 35 mg. sodium chloride/liter is deposited on each of 10 storage sites. The following relative intensity readings shown in Table l illustrate the reproducibility obtainable with the present invention:

TABLE I l Relative intensity Example No.: readings 1 109 EXAMPLES XlXV The following Table ll lists the composition of five solutions of sodium chloride and the relativelyincreasing response as a function of sodium ion concentration:

It should be understood that the flame photometer of the present invention can be utilized as an independent device or incorporated as one element of a compound automatic analyzer which performs many and varied functions.

Throughout the specification and the claims appended hereto, reference has been made to the term spectral flame burner." This term is meant to describe a gas burner having conduits therein for the passage of fuel and an oxidizer to the flame end thereof. There is no provision for the internal transportation of liquid sample material to be aspirated into the flame, as is known to be old in the prior art.

While the invention has been described with reference to preferred embodiments thereof, it should be understood by those skilled in the art that various changes in form and details may be made without departing from the true spirit and scope of the invention. All such modifications, etc. are considered to be within the scope of the present invention as defined by the claims appended hereto.

What I claim is:

l. A flame photometer comprising: a spectral flame burner for producing a flame, a spectrophotometer operatively positioned with respect to the flame, a transport tape located external to said flame burner, said transport tape comprising an elongated substrate of noncombustible material having a plurality of spaced apart apertures, a porous member of combustible material located in each aperture, sample deposition means for depositing a quantity of a liquid sample onto each porous member, and means for advancing said transport tape into the flame of said burner so as to cause the flame to impinge on each porous member.

2. The flame photometer of claim 1 further including drying means disposed between said sample deposition means and said spectral flame burner, said transport tape being advanced adjacent said drying means after sample deposition for eliminating unneeded volatile sample material from said porous member.

3. The flame photometer of claim 1 further including means to deposit a quantity of calibration standard material on said porous member, said calibration standard deposition means being situated along the path of transport tape travel prior to said spectral flame burner.

' 4. The flame photometer of claim 1 and further including means for supplying a stream of a fuel and a stream of oxygen to said spectral flame burner.

5. The flame photometer of claim 1 wherein said spectral flame burner has an analytical position and a nonanalytical position, and is mounted for pivotal movement from one position to the other.

6. The flame photometer of claim 1 wherein the spectrophotometer is positioned on the opposite side of said transport tape from said spectral flame burner.

7. The flame photometer of claim 1 wherein the spectrophotometer has a first chamber having a diffusely reflecting material coating on the inside thereof, a flame chamber attached to the outside of said first chamber, said first chamber and said flame chamber being in communication through an opening in their adjoining wall, said flame chamber being positioned directly over the flame of said spectral flame burner whereby it will receive the thermally excited vapor from said sample material, and at least one photodetector attached to the outside of said first chamber and in communication with said first chamber by means of an opening in the adjoining wall between said first chamber and said photodetector for monitoring the radiation transmitted to said first chamber through said opening.

8 The flame photometer of claim 7 wherein the diffusely reflective coating comprises magnesium oxide.

9. A flame photometer comprising: means for producing a flame. a spectrophotometer positioned for spectrally analyzing the flame, a sample aliquoter for dispensing a quantity of a liquid sample. a transport tape disposed external to said means for producing a flame for holding the liquid sample dispensed by the sample aliquoter and means for advancing the transport tape into the flame so as to cause the flame to burn the liquid sample held on said transport tape, said transport tape comprising an elongated strip on noncombustible material having an aperture and a porous member of combustible material for holding said liquid sample disposed in said aperture.

10. A flame photometer comprising: means for producing a flame, a spectrophotometer for analyzing the flame, dispensing means for dispensing a plurality of discrete quantities ofa liquid sample, a transport tape for holding said plurality of discrete quantities ofa liquid sample disposed external to said flame producing means and means for advancing said transport tape into said flame so as to cause at least some of 0 said plurality of discrete quantities of a liquid sample to burn, 

2. The flame photometer of claim 1 further including drying means disposed between said sample deposition means and said spectral flame burner, said transport tape being advanced adjacent said drying means after sample deposition for eliminating unneeded volatile sample material from said porous member.
 3. The flame photometer of claim 1 further including means to deposit a quantity of calibration standard material on said porous member, said calibration standard deposition means being situated along the path of transport tape travel prior to said spectral flame burner.
 4. The flame photometer of claim 1 and further including means for supplying a stream of a fuel and a stream of oxygen to said spectral flame burner.
 5. The flame photometer of claim 1 wherein said spectral flame burner has an analytical position and a nonanalytical position, and is mounted for pivotal movement from one position to the other.
 6. The flame photometer of claim 1 wherein the spectrophotometer is positioned on the opposite side of said transport tape from said spectral flame burner.
 7. The flame photometer of claim 1 wherein the spectrophotometer has a first chamber having a diffusely reflecting material coating on the inside thereof, a flame chamber attached to the outside of said first chamber, said first chamber and said flame chamber being in communication through an opening in their adjoining wall, said flame chamber being positioned directly over the flame of said spectral flame burner whereby it will receive the thermally excited vapor from said sample material, and at least one photodetector attached to the outside of said first chamber and in communication with said first chamber by means of an opening in the adjoining wall between said first chamber and said photodetector for monitoring the radiation transmitted to said first chamber through said opening.
 8. The flame photometer of claim 7 wherein the diffusely reflective coating comprises magnesium oxide.
 9. A flame photometer comprising: means for producing a flame, a spectrophotometer positioned for spectrally analyzing the flame, a sample aliquoter for dispensing a quantity of a liquid sample, a transport tape disposed external to said means for producing a flame for holding the liquid sample dispensed by the sample aliquoter and means for advancing the transport tape into the flame so as to cause the flame to burn the liquid sample held on said transport tape, said transport tape comprising an elongated strip on noncombustible material having an aperture and a porous member of combustible material for holding said liquid sample disposed in said aperture.
 10. A flame photometer comprising: means for producing a flame, a spectrophotometer for analyzing the flame, dispensing means for dispensing a plurality of discrete quantities of a liquid sample, a transport tape for holding said plurality of discrete quantities of a liquid sample disposed external to said flame producing means and means for advancing said transport tape into said flame so as to cause at least some of said plurality of discrete quantities of a liquid sample to burn, said transport tape comprising an elongated substrate of noncombustible material having a plurality of apertures and a porous member of combustible material disposed in each aperture. 